Cylinder Liner Through Hole for Sensor Protection

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Solution Overview

Problem

Direct cylinder pressure monitoring in large internal combustion engines is hindered by the limited lifetime of pressure sensors due to high temperatures and vibrations in the cylinder heads.

Innovation Solution

An anti-polishing ring with a through hole in the cylinder liner allows pressure transmission to a pressure sensor, positioned below the piston rings, reducing exposure to extreme temperatures and vibrations, and an anti-polishing ring protects the sensor from heat by creating a recess for the sensor and a groove for pressure transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If pressure sensors are arranged in the cylinder heads for direct pressure monitoring, then direct cylinder pressure measurement is achieved, but the lifetime of pressure sensors is limited due to high temperatures and vibrations

Engineering Contradiction:
Improvecylinder pressure measurementVSAvoidpressure sensor lifetime
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The pressure sensor is extracted from the high-temperature cylinder head environment and relocated to the cylinder liner wall where temperatures are lower. The through hole in the cylinder liner wall provides a pathway for pressure transmission while positioning the sensor in a more favorable thermal environment, thereby extending sensor lifetime while maintaining measurement capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The through hole in the cylinder liner wall acts as an intermediary structure that transmits cylinder pressure to the sensor without requiring the sensor to be directly exposed to the extreme cylinder head environment. This mediator allows pressure measurement while protecting the sensor from harmful thermal and vibrational conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a through hole is created in the cylinder liner wall for pressure transmission, then pressure sensor lifetime is extended by reducing temperature exposure, but the sensor may be exposed to harmful factors from the cylinder environment

Engineering Contradiction:
Improvepressure sensor lifetimeVSAvoidheat exposure to sensor
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The pressure sensor is nested within the recess of the cylinder liner wall, which is positioned behind the anti-polishing ring. This nested arrangement allows the sensor to be housed in a protected cavity that shields it from direct exposure to harmful cylinder environment factors while still enabling pressure transmission through the through hole.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The anti-polishing ring serves as a sacrificial or replaceable component that can be easily replaced if worn or damaged. It provides a simple mechanical solution to protect the expensive pressure sensor from harmful factors, allowing the sensor to operate in a more favorable environment while the anti-polishing ring absorbs the harsh conditions.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution extends the lifetime of pressure sensors by reducing exposure to high temperatures and vibrations, enabling reliable direct cylinder pressure measurement while protecting the sensor from heat.

Implementation Method 1

the outer surface of the anti-polishing ring comprises a groove, which extends in the axial direction from the upper end of the anti-polishing ring towards the lower end and is configured to allow transmission of pressure from the cylinder to the through hole of the cylinder liner

Methodology Applied
Scientific EffectPressure transmission: Pressure Gradient

Implementation Method 2

the wall of the cylinder liner comprises a through hole, which is configured to allow transmission of pressure from the cylinder to a pressure sensor

Methodology Applied
Scientific EffectPressure transmission: Pressure Gradient

Data Source

PatentEP3423693B1Cylinder liner and Anti-polishing ring
Publication Date: 2021.02.17 WARTSILA FINLAND OY
  • EP3423693B1 patent drawingFigure 1~2
  • EP3423693B1 patent drawingFigure 3

AI summary

The cylinder liner (5) for forming a cylinder (2) of a piston engine (1) comprises a through hole (9), which is configured to allow transmission of pressure from the cylinder (2) to a pressure sensor (3) and arranged in the wall of the cylinder liner (5) at such a height that when the cylinder liner (5) is mounted in an engine (1) for forming a cylinder (2) and a piston (6) inside the cylinder (2) is at top dead center, the hole (9) opens inside the cylinder (2) at a location that is above all the piston rings (10) of the piston (6).